temperamental

capricious, changeable, changeful, fickle, fluctuating, fluid, freakish, impulsive, inconstant, mercurial, mutable, uncertain, unsettled, unstable, unsteady, variable, volatile, whimsical

pouty, sulky

choleric, crabby, cranky, cross, crotchety, grouchy, grumpy, irascible, irritable, peevish, petulant, quick-tempered, short-tempered, snappish, snippety, snippy, testy, waspish

aimless, arbitrary, desultory, erratic, haphazard, hit-or-miss, irregular, random, scattered, slapdash, stray

ambivalent, hesitating, shaky, shilly-shally, shilly-shallying, vacillating, wavering

dicey, undependable, unreliable, untrustworthy

adaptable, mobile, protean, versatile